90 likes | 212 Views
Distributed diagnosis of telecomunications networks. Armen Aghasaryan. the diagnosis problem : definition. Fault propagation – causality Alarm interleaving – concurrency Distributed processing. diagnoser. diagnoser. supervision. telecommunications network.
E N D
Distributed diagnosis of telecomunications networks Armen Aghasaryan
the diagnosis problem : definition • Fault propagation – causality • Alarm interleaving – concurrency • Distributed processing diagnoser diagnoser supervision telecommunications network
the diagnosis problem : SDH example alarm LOS notification State_Change() + vertical propagation alarm TF notification State_Change() ADM ALS ADM alarm LOS + vertical propagation alarm TF OpticalSPITTPBdir OpticalSPITTPBdir
Can be automated fault model-based approach Topology / Connections Device (NE) specificities Managed Objects (MIB) Experts knowledge Fault Model Diagnosis process diagnosed fault scenario(s) alarms
fault model-based approach: model inversion • Fault model replicates the fault behaviour of the network • initial faults, their propagation, and the observed alarms • Diagnosis algorithms inverse the model! • distributed dynamic programming methods • Uncertainties in the behaviour • probabilities can be introduced in the model Fault model generated alarms fault scenario Diagnosis process diagnosed fault scenario(s) observed alarms
Montrouge fault model-based approach : methodology • Structural model (ITU-T…) • physical network topology • network elements • connections model • Behavioural model SDH Ring
Managed Object fault model-based approach : behavioural model • Elementary Sequence Diagram (UML extension) • pre-condition: attributes, received messages • action: sending messages, changing attribute values • post-condition: attributes, sent messages
detection of the emission interruption and respective actions detection of the absence of signal caused by the distant device actions in case of the absence of signal automatic laser switch mechanism fault model-based approach : behavioural model
Aubervilliers Montrouge St Ouen Gentilly fault model-based approach : correlation tree AU-AIS AU-AIS disabled AU-AIS AU-AIS AU-AIS disabled AU-AIS MS-AIS MS-AIS TF disabled LOS disabled LOS TF